The pneumatically operated spindle wrench of this invention is classified in Class 90 Subclass 11D.
In U.S. Pat. No. 4,128,043 issued Dec. 5, 1978, R. Grassl discloses a quick release tool holder suitable for use with a vertical milling machine.
U.S. Pat. No. 4,059,066 discloses an additional improvement in quick release tool holders for a vertical milling machine.
Existing toolholder changing devices require new toolholders provided with extensions. These systems do not work on rotary mounting or release, but on a vertical retraction system. When changing toolholders in the conventional manner, one needs a wrench and hammer. The hammer is used to hit the drawbar on the top, loosening the toolholder mounted within the tapered spindle.